Incendiary cutting torch for underwater use

ABSTRACT

An incendiary torch having a cylindrical housing with a nozzle positioned at one end thereof. The nozzle is held in place by a retainer cap threadedly attached to the housing which includes a diaphragm overlying the aperture in the nozzle thereby preventing the ambient environment from entering the torch chamber. The end of the torch housing may be connected to a work holding device.

United States Patent 1 1 Helms et a1.

3,713,636 Jan. 30, 1973 lNCENDlARY CUTTING TORCH FOR UNDERWATER USEInventors: Horace H. Helms, Silver Spring; Alexander G. Rozner,Bethesda, both of Md.; Dana E. Spencer, Alexandria,Va,

Assignee: The United States of America as represented by the Secretaryof the Navy Filed: Sept. 22, 1970 Appl. No.: 74,434

US. Cl. ..266/23 NN, 102/37.8 Int. Cl ..B23k 7/00, C06d 1/10 Field ofSearch.....266/23 P, 23 R, 23 F, 23 HH, 266/23 NN;102/37.8, 52, 54;431/158, D10. 25; 126/263; 175/14; 239/309; 222/541 PrimaryExaminerRobertD. Baldwin AIl0rney-R. S. Sciascia and .l. A. Cooke 57;ABSTRACT An incendiary torch having a cylindrical housing with i anozzle positioned at one end thereof. The nozzle is held in place by aretainer cap threadedly attached to the housing which includes adiaphragm overlying the aperture in the nozzle thereby preventing theambient environment from entering the torch chamber. The end of thetorch housing may be connected to a work holding device.

5 Claims, 5 Drawing Figures SHEET 1 OF 2 PATENTEDJAN 30 I915 INVENIORSHorace H. Helms Alexander G. Rozner Dana E. Spencer A ORNEY INCENDIARYCUTTING TORCH FOR UNDERWATER USE BACKGROUND OF THE INVENTION Thisinvention relates generally to pyrotechnic cutting devices and moreparticularly to a pyrotechnic torch.

It has been found necessary in such work as clearing or salvageoperations that relatively thick objects made of metal, ceramic,plastic, or the like must be cut through in a very short length of time.Such operations often take place in underwater environments, such forexample, as in the salvaging of sunken vessels. Additionally, operationsof this nature must often be accomplished in extremely short timeintervals for various reasons such as, for example, in the case ofunderwater work, the lack of sufficient supplies of air available to theoperator to enable him tospend extended periods of time beneath thesurface.

In the past, various torch devices have been designed, some specificallyto perform in underwater environments. Whether these prior torches haveused gaseous or liquid fuel components, they operate on the commonprinciple that the cutting energy is transferred from the torch to thework by means of jets of gas produced within the torch by some chemicalreaction.-

For instance, in gas cutting" both above and beneath the water, heat issupplied by burning a mixture of oxygen and a suitable combustible 'gas,such, for example, as acetylene. The gases are mixed in a torch, the tipof which is usually made with a central orifice for theoxyacetylene-cutting jet. When used in underwater environments this typeof cutting torch must be surrounded by a protecting bell through whichcompressed air is forced to evacuate the immediately surrounding area ofwater.

Various difficulties arise with the use of torches of the type referredto hereinbefore. For example, the volume of oxygen (in cubic feet perhour at l atm and 70C) necessary to cut heavy sections of materialranges from 80 to 120 times the thickness (measured in inches) of thematerial to be cut. Together with the acetylene supply, the supply tanksbecome quite bulky and hard to manage, especially when used underwater.The cutting speeds attained are relatively slow, ranging between 6 and 2inches per minute depending upon the thickness of the material to becut. Higher speeds often result in the loss of the cut and consequentspoilage of the material. Some gases, such as acetylene, cannot be usedat pressures above psig for safety reasons and, therefore, their use inunderwater cutting at any substantial depths is severely limited.Further, oxyacetylene torches have not proved to be an effective cuttingdevice for copper and aluminum workpieces.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is toprovide a new and improved incendiary cutting device.

Another object of the present invention is to provide a new and improvedincendiary torch for use in underwater environments.

Still another object of the present invention is to provide a new andimproved incendiary torch for use at relatively great depths beneath thesurface.

A further object of the instant invention is to provide a new andimproved underwater cutting torch which will cut through thick materialrelatively quickly.

A still further object of the instant invention is to provide a new andimproved incendiary device which can effectively pierce through ordestroy a particular material.

Another still further object of the instant invention is to provide anew and improved underwater cutting torch which is both compact,inexpensive and easy to handle.

Still another further object of this invention is the 0 provision of acutting torch readily attachable to a work-holding device.

Briefly, in accordance with one embodiment of this invention, these andother objects are attained by providing a torch having a chamber and anappropriate nozzle through which a high velocity jet produced byreactants contained therein is directed which impinges against theworkpiece thereby cutting the same.

BRIEF DESCRIPTION OF THE DRAWING A more complete appreciation of theinvention and many of the attendant advantages thereof will be readilyappreciated as the same becomes better understood by reference to thefollowing detailed description when considered in connection with theaccompanying DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now tothe drawings wherein like reference characters designate identical orcorresponding parts throughout the several views, and more particularlyto FIG. 1 thereof wherein the incendiary torch 10 of the presentinvention is shown as including cylindrical housing 12 having an openend 14, a substantially closed end 16 and a cylindrical bore 17 alongthe length thereof. The open end l4.is provided with an internal thread18 extending a short distance into the elongate bore 17. An annulargroove 20 is formed in the inner edge extremity of end 14 whichcooperates with thread 18 and provides a seat for a conventional O-ringseal 22.

A tubular liner 24 formed of heat resistant material such, for example,as graphite or a phenolic, may be slidably positioned within bore 17,the liner 24 having an outer surface 26 which conforms to the surface ofbore 17 of housing 12. Axial movement of liner 24 is limited by theclosed end 16 of housing 12 and the upper surface of nozzle 50 as willbe discussed in greater detail hereinafter.

The closed end 16 of housing 12 has a threaded bore 30 formed centrallytherein which is adapted to threadably receive a cylindrical plug 32having cooperating threads formed on the external surface thereof. Theplug 32 has a pair of cylindrical bores 34 formed therein for passage ofinsulated electrical conductors 36 whose purpose will be explained ingreater detail hereinafter. The conductors 36 are fixed within bores 34by conventional means such as a suitable potting compound which willwithstand relatively high internal pressure. A conventionalelectroresponsive squib device 38 is connected to the internal ends ofconductors 36.

The inner surface 42 of liner 24 defines an axial chamber 40 which isfilled with fuel in the form of a plurality of cylindrical pellets 44the composition of Y which will be discussed in greater detailhereinafter. The pellets may be of a solid type stacked one upon theother in the axial chamber 40 in which case the conductors 36 must bepositioned along the inside surface of liner 24 and lead to the lowerportion of the torch where the squib device 38 is positioned beneath thelowermost pellet .44 (as seen in FIG. 3). Alternatively, the pellets 44may have a central circular bore 46 formed therein and upon stacking thepellets in the chamber 40 (as seen in FIG. 1) bores 46 are alignedthereby forming a single elongate bore which extends from the closed end16 of housing 12 to a' point substantially adjacent the end of liner 24.In this case the squib device 38 may be positioned to be situated withinthe bore 46 of the uppermost pellet 44 and interposed between adjacentpellets are layers 48 of a burning resistant material such, for example,as magnesium oxide paint for reasons which will become clearer as theoperation of the torch is more fully described. The elongate bore formedby the alignment of bores 46 is filled with a powder 47 of thesamecomposition as pellets 44 as is the cavity formed below the lowermostpellet.

The fuel pellets 44 and heat resistant liner 24 are retained in positionwithin the housing 12 by means of cylindrical nozzle 50 in cooperationwith retainer cap 28.

As illustrated by FIG. 2, the nozzle 50 may be any one of a number ofnozzle configurations including an integral annular flange 51 at theupper end thereof and having a tapered bore 52 in one face which reachesan apex, as at 54, substantially midway along the axial length thereof.The type of cut desired to be performed by the torch on a workpiece willdetermine the geometric configuration of the nozzle aperture- 56. FIG.2a illustrates a single hole nozzle wherein a single central bore 57 isaxially formed in the nozzle for use in small diameter, relatively deeppenetration of the work. Nozzles, such as those shown in FIG. 2b where,for example, five bores 57 are formed, may be used to create much largerdiameter openings in targets. The nozzle of FIG. 2c, having narrowelongated slots, such as 58 cooperating with the bores 57 enablecontinuous linecuts in plate or most efficient cutting of cables, chainsor the like.

Returning to FIG. 1, the nozzle is fitted into the open end 14 ofhousing 12 and fits within chamber 40. i

The nozzle 50 is retained in this position by the retainer cap 28 whichfunctions as a nozzle receiving cup device defined by a cylindrical wallportion having a smooth inner surface 62, a threaded outer surface 64and an I upper edge 65. An integrally formed bottom portion 66 closesone end of the cylinder and further forms a circumferentially extendingflange 67. The bottom portion 66 has a planar inner surface 68 and anouter surface 70 which is beveled inward to define a centrally disposed,relatively thin diaphragm 74 which overlies bores 57 thereby preventingthe ambient environment from entering into the torch chamber through thenozzle 50. As noted hereinbefore, the nozzle 50 fits within threadedouter surface 64 of the retainer cap 28 is adapted to be threadablyengageable with the internal threads 18 of housing 12. Before theretainer cap is threadably engaged to the torch housing 12, the O-ringseal 22 is positioned within the annular groove 20 and is fixedly heldtherein by the flange 67 of bottom portion 66 when the retainer cap 28is in its working position. It is to be particularly noted that theupper surface of flange 67 does not abut the lower surface of cylinder12 thereby enabling a viable seal to be achieved by the cooperation ofthe retainer flange 67 and O-ring 22.

Referring now to FIG. 3, a modified version of the torch 10 is shown asbeing affixed to one of many types of conventional work-holding devices,generally identified as 75, threadedly connected to the bottom of torchhousing 12'. Nozzle 50 is held within housing 12 constraining a liner 24which is positioned within the housing in the same manner as liner 24 inFIG. 1. Work-holding device 75 includes a substantially rectangularupper holder member 82 which serves both the function of the retainercap 28 of FIG. land also of a vise-type member to fixedly hold aworkpiece in position for cutting. A circular central cavity 84 isformed in the holder member 82 in which nozzle 50 is adapted to bepositioned. An annular channel 86 is formed coaxially with the cavity 84having a threaded wall 88, the channel being formed so as to bethreadably connectable to the torch housing 12. The lower surface 90 ofthe upper holder member 82 is beveled as at 92 thereby defining acircular diaphragm portion 94 located immediately below the cavity 84.Thus, it can be seen that upon threadedly engaging the torch housing 12'with the upper holder 82, the latter acts similarly to the retainer cap28 of FIG. 1 by retaining the nozzle 50 fixed in place. Conventionalthread sealant (not shown) of nylon, for example, may be positionedaround threads 88 to provide a watertight seal.

Formed in each corner of the upper holder member 82 is a circular bore96 through which passes an externally threaded elongate cylindrical rod98 having a bifurcated end 100. Two adjacent rods 98 (only one shown)are constrained against movement by a pair of threaded nuts 102 engagedwith rod 98 and are adapted to cooperate with the upper and lowersurfaces of the holder member 82 thereby prohibiting any substantialaxial movement of the rods. The remaining two rods 98 (only one of whichis shown) are movably heldin position by internally threaded nut membersI 104 threadably engaged to the rods and abutting the upper surface ofholder member 82. The nut members 104 include enlarged portions tofacilitate manual rotation thereof thereby raising or lowering rods 98in an obvious manner.

Pivotally connected to the bifurcated ends of rods 98 are a pair oftransverse bar members 106, each bar member having an end, such as 108pivoted to a fixed rod member with the opposite end, such as 110,pivoted to a movable rod member. Centrally disposed on each bar member106 and on opposite sides thereof each cutout portion 112 and fixed tothe lower surface 90 of holder member 82 is a guide member 114 having anarcuate shaped surface 116 formed therein. The arcuate surfaces 112 and116 may cooperate to hold a workpiece such, for example, as a cable orpipe 118 as shown in phantom in FIG. 3. After the workpiece is placedbetween the upper holder member 82 and the transverse bar members 106,nut members 104 are rotated in a suitable direction thereby drawing rods98 upward resulting in a vise-likeaction between the arcuate surfaces.Should a workpiece be too large to easily fit within the work holdingdevice 75, nuts 102 may be bore 46 is filled with the powder 47extending into the tapered bore 52 of nozzle 50 thereby forming acontinuous column of uncompressed fuel material as seen in P16. 1.

Upon connecting an electrical energy source to the conductors 36 whichmay be accomplished; for example, by remote control, theelectroresponsive squib 38 is actuated thereby igniting the column offuel powder 47 along its entire length substantially simultaneously.This ignition initiates the reaction of the fuel pellets 44 as discussedhereinafter.-ln the embodiment shown in FIG. 1, it is desired to havethe pellets propagate in a radial fashion to insure a reasonably uniformpressure distribution in the torch chamber 40 and the inhibiting layers48 thereby prevent any substantial axial propagation from occuring.

Upon initiation of the reaction of fuel pellets 44, an instantaneousexothermic reaction'is undergone during the subsequent alloying andoxidation of the elements. The diaphragm 74 assures that the torch issealed, both internally and externally, so that the gas pressure ismaintained. The reaction will go to completion whether it be. locatedunderwater, above surface, or in outer space. The Teflon, in thepresence of the large quantities of heat produced, decomposes into a gasthereby increasing the pressure within the torch considerably. When thepressure inside the torch exceeds the strength of the diaphragm, thediaphragm fractures and the expanding gases will force themoltenmaterial through the nozzle. Temperatures in the range of 2400 Cto 3200 C result from this reaction and these high temperatures coupledwith the high jet velocity of the molten metal forced through the nozzle50 by the great pressure produced within the torch provides a cuttingaction which in almost all cases achieves the desired cut in no morethan one second. Should the alternative of solid cylindrical fuelpellets be utilized as shown in FIG. 3, the chemical reaction wouldproceed in an axial 6 fashion in an upward direction within the torchchamber since ignition would occur at the lowermost portion of thetorch.

The housing 12 should be of sufficient thickness to withstand theinternal pressurization of the chamber 40 following ignition. Afterignition within the torch, internal pressure builds up rapidly in thechamber 40 due to expanding gases until a predetermined upper limit isreached whereupon the diaphragm 74 is broken and the molten jet isreleased at a high velocity.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise. than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A tool adapted to be used as a cutting torch comprising:

a fuel receiving chamber formed in a tubular housing having a closed endand an open end;

a nozzle connected to the open end ofthe tubular housing and having atleast one aperture therethrough communicating with said fuel receivingchamber; 7

fastener means in the open end of the housing for receiving said nozzle;

a diaphragm coupled to said fastener means for scaling said nozzleaperture in a closed mode and adapted to withstand a predeterminedinternal 7 pressure;

an electroresponsive squib contained within said fuel receiving chamberat the closed end thereof; and

remotely controllable means external to said housing for activating saidelectroresponsive squib.

2. The tool as recited in claim 1 further including a solid fuelcomposition positioned within said fuel receiving chamber which uponignition reacts to form a molten liquid which exits from said nozzle asa high velocity jet.

' 3. An incendiary cutting torch adapted for use underwater comprising:I

a cylindrical housing having an elongate cylindrical bore formed thelength thereof defining a fuel receiving chamber and having an open endand a closed end; Y

a solid fuel composition positioned within said fuel receiving chamber;

an electroresponsive squib embedded in said solid fuel composition;

a nozzle detachably' connected to said open end of said housing andhaving at least one aperture therein;

a retaining member connected to said open end of said housing having acylindrical cavity portion formed therein to receive said nozzle and abottom portion integral therewith effectively closing said open end; and

a diaphragm integral with said-retaining member adapted to withstand apredetermined internal pressure within said fuel receiving chamber.

4. An incendiary torch as recited in claim 3 wherein said elongatecylindrical bore has a burning resistant liner positioned on the surfacethereof.

5 An incendiary torch as recited in claim 3 wherein:'

said bottom portion of said retaining member is provided with a pair ofguide members having shaped surfaces formed therein to receiveappropriate workpieces;

a pair of transverse bar members connected to said retaining member andadapted to be movable towards or away from said retaining member by aplurality of threaded rod members.

1. A tool adapted to be used as a cutting torch comprising: a fuelreceiving chamber formed in a tubular housing having a closed end and anopen end; a nozzle connected to the open end of the tubular housing andhaving at least one aperture therethrough communicating with said fuelreceiving chamber; fastener means in the open end of the housing forreceiving said nozzle; a diaphragm coupled to said fastener means forsealing said nozzle aperture in a closed mode and adapted to withstand apredetermined internal pressure; an electroresponsive squib containedwithin said fuel receiving chamber at the closed end thereof; andremotely controllable means external to said housing for activating saidelectroresponsive squib.
 1. A tool adapted to be used as a cutting torchcomprising: a fuel receiving chamber formed in a tubular housing havinga closed end and an open end; a nozzle connected to the open end of thetubular housing and having at least one aperture therethroughcommunicating with said fuel receiving chamber; fastener means in theopen end of the housing for receiving said nozzle; a diaphragm coupledto said fastener means for sealing said nozzle aperture in a closed modeand adapted to withstand a predetermined internal pressure; anelectroresponsive squib contained within said fuel receiving chamber atthe closed end thereof; and remotely controllable means external to saidhousing for activating said electroresponsive squib.
 2. The tool asrecited in claim 1 further including a solid fuel composition positionedwithin said fuel receiving chamber which upon ignition reacts to form amolten liquid which exits from said nozzle as a high velocity jet.
 3. Anincendiary cutting torch adapted for use underwater comprising: acylindrical housing having an elongate cylindrical bore formed thelength thereof defining a fuel receiving chamber and having an open endand a closed end; a solid fuel composition positioned within said fuelreceiving chamber; an electroresponsive squib embedded in said solidfuel composition; a nozzle detachably connected to said open end of saidhousing and having aT least one aperture therein; a retaining memberconnected to said open end of said housing having a cylindrical cavityportion formed therein to receive said nozzle and a bottom portionintegral therewith effectively closing said open end; and a diaphragmintegral with said retaining member adapted to withstand a predeterminedinternal pressure within said fuel receiving chamber.
 4. An incendiarytorch as recited in claim 3 wherein said elongate cylindrical bore has aburning resistant liner positioned on the surface thereof.